• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.4
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• pp.252-256
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• 2003

In this paper we describe the status of a silicon-based microelectrode for neural recording and an advanced neural interface. We have developed a silicon neural probe, using a combination of plasma and wet etching techniques. This process enables the probe thickness to be controlled precisely. To enhance the CMOS compatibility in the fabrication process, we investigated the feasibility of the site material of the doped polycrystalline silicon with small grains of around 50 nm in size. This silicon electrode demonstrated a favorable performance with respect to impedance spectra, surface topography and acute neural recording. These results showed that the silicon neural probe can be used as an advanced microelectrode for neurological applications.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1349-1351
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• 2001

Polycrystalline diamond films are deposited by using a microwave plama CVC system, where the bias-enhanced nucleation (BEN) method is employed. Effects of the varying microwave power, the surface treatment by hydrogen plasma, and the cyclic hydrogen etching during deposition on the crystallinity as well as on the surface roughness of deposited films are examined by Raman spectroscopy, SEM, and AFM. A novel method for achieving a smoother diamond surface is also suggested through the indirect wafer bonding and back-side polishing.

• ETRI Journal
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• v.24 no.5
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• pp.398-400
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• 2002

Using $Cr_2O_3$ thin film, we developed a novel etch-stop technique for the protection of silicon surface morphology during deep ion coupled plasma etching of silica layers. With this technique we were able to etch a silica trench with a depth of over 20 ${\mu}m$ without any damage to the exposed silicon terrace surface. This technique should be well applicable to fabricating silica planar lightwave circuit platforms for opto-electronic hybrid integration.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1078-1082
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• 2003

A feasibility study for the fabrication of master replication with nanostructures by Nanoimprint Lithography (NIL) was investigated for application of polymer Photonic Bandgap (PBG) devices used in photonic IC. Large area gratings of $9{\times}15(mm^2)$ with p = 400 nm was successfully embossed on PMMA on silicon wafer and the embossing parameters (temperature, pressure, time) were established. A precise control of $O_2$ plasma Reactive Ion Etching (RIE) process time allowed window opening over the whole area despite the presence of wafer bending. Master replication with aspect ratio 1 was successfully fabricated, but master replication with aspect ratio 3 needs to optimize parameters. All replications were done in a NIL process.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.35-38
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• 1995

We proposed in this paper a systematic way for analyzing discrete event dynamic systems to classify faults and failures quantitatively and to find tolerable fault event sequences embedded in the system. An automated failure diagnosis scheme with respect to the nominal normal operating event sequences and the supervisory control problem for tolerable fault event sequences is presented. Moreover the supervisor failure diagnosis problem with respect to the tolerable fault event sequences is considered. Finally, a plasma etching system example is presented.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.12
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• pp.115-121
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• 1995

A mask for x-ray lithography is fabricated with SiN membrane and WTi absorber. SiN membrane is deposited by plasma enhanced chemical vapor deposition, and the stress of SiN membrane is controlled to be less than 100 MPa by rapid thermal annealing. WTi absorber is reactively deposited by DC-magnetron type sputter, and the working gases are argon and nitrogen. Added nitrogen is contributed to the stress of WTi absorber. The stress of WTi absorber is controlled to be less than $\pm$ 100 MPa by controlling the deposition pressure. 10$\mu$m WTi pattern is delineated on SiN membrane by dry etching technique.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.22-25
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• 2004

In this study, BST thin films were etched with inductively coupled $CF_4/(Cl_2+Ar)$ plasmas. The etch characteristics of BST thin films as a function of $CF_4/(Cl_2+Ar)$ gas mixtures were analyzed using quadrupole mass spectrometry (QMS) and optical emission spectroscopy (OES). The maximum etch rate of the BST thin films was 53.6 nm/min because small addition of $CF_4$ to the $Cl_2/Ar$ mixture increased chemical effect. The optimum condition appears to be under a 10 % $CF_4/(Cl_2+Ar)$ gas mixture in the present work.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.54-56
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• 2005

QMS를 이용하여 chlorine based 유도결합 플라즈마 내 이온의 거동에 대한 분석을 하였다. 플라즈마 진단 가스로는 AT 가스에 $BCl_3$을 첨가하였으며 공정 압력을 변화하며 플라즈마 특성 변화를 분석하였다. 가스 혼합비에 따른 이온의 상대적인 밀도 변화에서 소량의 Ar가스의 첨가는 $BCl_3$ 가스의 이온화를 도와 $Cl^+$ 이온이 증가하는 현상을 보이며 Ar과 $BCl_3$의 이온화 에너지의 차이로 인해 $BCl_3$ 가스의 첨가비가 적을 수록, RF Power가 증가하며, 공정 압력이 낮올 수록 이중 피크 구조의 이온 에너지 분포를 확인 할 수 있었으며 이는 이온이 접지 전극에의 도달 시간과 평균 플라즈마 전위의 변화 때문이라고 사료된다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.54-54
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• 2005

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.95-95
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• 2009

대기압 플라즈마 발생장치를 이용한 식각장비 개발은 낮은 공정단가, 저온 공정, 다양한 표면처리 응용 효과와 같은 이점을 가지고 있어 현재, 많은 분야에서 연구되고 있다. 본 연구에서는, dielectric barrier discharge(DBD) 방식을 이용한 대기압 발생장치를 통해 평판형 디스플레이 제작에 응용이 가능한 $SiO_2$ 층의 식각에 대한 연구를 하였다. $N_2/NF_3$ gas 조합에 $CF_4$ 또는 $C_{4}F_{8}$ gas를 부가적으로 첨가하였다. 이때 N2 60 slm / NF3 600 sccm/CF4 7 slm/Ar 200 sccm의 gas composition에서 최대 260 nm/min의 식각 속도를 얻을 수 있었다.